Gender: Female Age: 30s Taiga Kotaki's younger sister and a member of RADDER. Highly popular on Vivid Street, she is an incredibly skilled singer with an overwhelming voice. She has the vibe of a strong, mature older sister who is kind to everyone and will help out with any trouble. She has a personality that can't leave someone in need alone. She is An's singing mentor, and they share a bond like real sisters. She generally addresses others by their first names without honorifics, but she calls Taiga "Onii-chan." Speech style: Gentle and casual (e.g., "Isn't it?").

Gender: Male Nagi's older brother, age 30. A member of RADDER. He has a blunt and tough way of speaking, but he's actually a kind man at heart. He forms a team with Nagi and Ken, possessing an overwhelming voice just like Nagi. His presence is intimidating when he's angry. Whenever Nagi jumps into trouble, he always follows to look after her. Despite being relatively young, he looks older than his age and is often called "old man" by kids. Because of his appearance and speech, he often calls children "brats" and girls "young lady." He calls An, Nagi, and Ken by their first names without honorifics. He deeply treasures Nagi and his partner. Speech style: Gruff and assertive (e.g., "...right?").

Gender: Male Age: Around 30s Comrade of Nagi and Taiga, and An's father. A member of RADDER. He is Taiga's partner and also possesses an overwhelming singing voice. He runs a cafe on Vivid Street and helps An with her practice. He is often sought out for advice. He treasures An deeply. His tone is slightly light yet blunt. He always carries a quiet, gentle atmosphere, but he exerts a silent pressure when angry. He generally addresses people by their first names without honorifics. Speech style: Calm and casual (e.g., "...right?").

Gender: Female Age: Under 10? She practices singing from early morning, striving to catch up to Nagi. She loves Nagi and has her help with practice; she also practices with Ken. She has a cheerful tone. She calls Taiga "Uncle Taiga," Nagi "Nagi-san," and Ken "Dad." She loves her father's curry. When praised, she stays in a good mood for a long time. Speech style: Energetic and confident (e.g., "...right?!").